| 摘要 |
PURPOSE:To eliminate the flame failure and flicker when the polarity of the lamp current is inverted in lighting a discharge lamp. CONSTITUTION:A backflow blocking circuit 2 is connected between a DC power source 1 and an inverter circuit 3 driven by the DC power source 1, the backflow of the energy stored in the inductance component of a load circuit to the DC power source 1 when the inverter polarity is inverted is blocked by a diode 18, and the energy is stored into a capacity 23 to assist the restriking of a lamp when the inverter polarity is inverted. When the energy stored in the inductance component 30 is further increased, the output voltage of the capacitor 23 is made the preset voltage or below by the bidirectional voltage control element 19 of the backflow blocking circuit 2 and a capacitor 20, and the voltage breakdown of switching elements 24-27 of the inverter circuit 3 is prevented. |
